1. Technical Field
This application generally relates to data storage, and more particularly to techniques used in connection with storage requirements for data protection.
2. Description of Related Art
Computer systems may include different resources used by one or more host processors. Resources and host processors in a computer system may be interconnected by one or more communication connections. These resources may include, for example, data storage devices such as those included in the data storage systems manufactured by EMC Corporation. These data storage systems may be coupled to one or more servers or host processors and provide storage services to each host processor. Multiple data storage systems from one or more different vendors may be connected and may provide common data storage for one or more host processors in a computer system.
A host processor may perform a variety of data processing tasks and operations using the data storage system. For example, a host processor may perform basic system I/O operations in connection with data requests, such as data read and write operations.
Host processor systems may store and retrieve data using a storage device containing a plurality of host interface units, disk drives, and disk interface units. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels to the storage device and the storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical disk units. The logical disk units may or may not correspond to the actual disk drives. Allowing multiple host systems to access the single storage device unit allows the host systems to share data in the device. In order to facilitate sharing of the data on the device, additional software on the data storage systems may also be used.
Storage space is allocated for storing a primary set of user data. Additional storage may be used in connection with providing data protection for the primary set of data. Data protection may be provided by a data protection process used to facilitate obtaining copies of data, or portions thereof, at one or more points in time. Examples of data protection techniques include snapshot and data replication facilities. The copy of data provides “protection” in that the copy may be used upon the occurrence of an event causing data failure, for example, when the primary or original data is destroyed, corrupted, or otherwise unavailable. A user may make a determination as to what amount of storage is allocated or provisioned for use with data protection both initially and over time. Additionally, monitoring and adjusting the amount of storage allocated for data protection may be performed manually by a user. The foregoing has drawbacks, for example, in that it is reliant on the user's availability and reliance to keep up with ongoing monitoring and adjustment to ensure that a proper amount of storage is allocated for data protection purposes. The foregoing is also dependent on the user's knowledge and abilities to make appropriate assessments as to when adjustments are needed as well as an amount for any adjustment. Additionally, the amount of storage needed for data protection may vary over time further adding complexity. If the user does not allocate additional storage for data protection until current storage allocations for data protection are exhausted, there is a potential for data loss since data protection processing may cease until such additional storage is allocated. Also, allocating too much additional storage for data protection contributes to inefficient storage utilization.